Communication Between Portable Apparatus and Counterpart Apparatus

ABSTRACT

A portable apparatus, a counterpart apparatus and communication method are disclosed. The communication method comprises: communicating wirelessly an identifier from a portable apparatus to a counterpart apparatus by an induction-based magnetic field; executing a pairing protocol utilizing the identifier between the radio transceiver of the portable apparatus and a radio transceiver of the counterpart apparatus by electric radiation; and communicating information between the radio transceiver of the portable apparatus and the radio transceiver of the counterpart apparatus by electric radiation.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority based on Finnish Patent Application No.20085280, filed Apr. 3, 2008, which is incorporated herein by reference.

BACKGROUND

1. Field

The invention relates to a portable apparatus, a counterpart apparatus,and a communication method.

2. Description of the Related Art

A portable apparatus, such as a heart rate monitor, may communicateinformation, such as heart activity data, to a counterpart apparatus,such as an exercise apparatus, over a radio link. In order to be able tocommunicate, the radio transceivers of the portable apparatus and thecounterpart apparatus need first to be paired together. This is achievedby executing a pairing protocol. However, as there may be many portableapparatuses present, and possibly also many counterpart apparatuses maybe present, it may be problematic to find out which portable apparatuswishes to be paired together with a specific counterpart apparatus.

SUMMARY

The present invention seeks to provide improvements in the communicationbetween a portable apparatus and a counterpart apparatus.

According to an aspect of the present invention, there is provided aportable apparatus as specified in claim 1.

According to another aspect of the present invention, there is provideda counterpart apparatus as specified in claim 8.

According to another aspect of the present invention, there is provideda communication method as specified in claim 15.

According to another aspect of the present invention, there is providedanother portable apparatus as specified in claim 16.

According to another aspect of the present invention, there is providedanother counterpart apparatus as specified in claim 17.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention are described below, by way ofexample only, with reference to the accompanying drawings, in which

FIG. 1 illustrates a portable apparatus and a counterpart apparatus;

FIGS. 2, 3 and 4 illustrate various embodiments of a portable apparatusand a counterpart apparatus; and

FIG. 5 is a flowchart illustrating an embodiment of a communicationmethod.

DETAILED DESCRIPTION

The following embodiments are exemplary. Although the specification mayrefer to “an”, “one”, or “some” embodiment(s) in several locations, thisdoes not necessarily mean that each such reference is to the sameembodiment(s), or that the feature only applies to a single embodiment.Single features of different embodiments may also be combined to provideother embodiments.

FIG. 1 illustrates a portable apparatus 100 and a counterpart apparatus106. FIG. 1 is a simplified block diagram that only shows some elementsand functional entities, all being logical units whose implementationmay differ from what is shown. The connections shown in FIG. 1 arelogical connections; the actual physical connections may be different.It is apparent to a person skilled in the art that the describedapparatuses 100, 106 may also comprise other functions and structures.It should be appreciated that some functions, structures, and elements,and the protocols used for communication are irrelevant to the actualinvention. Therefore, they need not be discussed in more detail here.The specifications of apparatuses 100, 106 develop rapidly. Suchdevelopment may require extra changes to an embodiment. Therefore, allwords and expressions should be interpreted broadly and they areintended to illustrate, not to restrict, the embodiments. Although theapparatuses 100, 106 have been depicted as separate single entities,different parts may be implemented in one or more physical or logicalentities.

The term ‘portable apparatus’ 100 may refer to a complete device that auser is capable of carrying around, or to a part of such a device. Thecomplete device 100 may be a heart rate monitor, a heart ratetransmitter wearable on the chest of a user, a personal measurementdevice, a wrist-worn measurement device, or a subscriber terminal of aradio system, for example. A part of such a device 100 may be anelectronic circuit implementing the described behavior of the portableapparatus 100 embodiments. The electronic circuit may comprise logiccomponents, standard integrated circuits, and/or application-specificintegrated circuits (ASIC).

The term ‘counterpart apparatus’ 106 may refer to a complete devicecapable of interacting with the portable device 100, or to a part ofsuch a device. The complete device 106 may be a computer, an exerciseapparatus, or a health club apparatus, for example. A part of such adevice 106 may be an electronic circuit implementing the describedbehavior of the counterpart apparatus 106 embodiments. The computer maybe a personal computer (such as a desktop computer, a laptop computer,or a palmtop computer). The computer may also be a server computer. Thecomputer may store and process heart activity data of countless persons.The computer may be team specific, i.e. it is used to process the heartactivity data of a certain team. Alternatively, the computer may provideheart activity data storage and analysis services to a wide audience, asa world-wide web (WWW) server over the Internet, for example. If thecounterpart apparatus 106 is an exercise apparatus, such as a treadmill,the training load may be regulated, a diary may be stored, etc.utilizing the communication to be described later on.

The portable apparatus 100 comprises two communication devices: aninduction-based transmitter 102 and a radio transceiver 104.Correspondingly, the counterpart apparatus 106 comprises aninduction-based receiver 108 and a radio transceiver 110.

Consequently, two different wireless communication technologies areused: induction-based technology utilizing a magnetic field, and aradio-based technology utilizing electric radiation. It is to be notedthat both technologies involve both the magnetic field and the electricradiation, but the separation is based on the fact that either one ofthese physical phenomena predominates and is only used for thecommunication in each technology.

A crucial difference between these two communication technologies is thesignal attenuation as a function of the length of a signal propagationpath. In the induction-based communication technology, the signal levelis inversely proportional to the third power of the length of the signalpropagation path, whereas in the radio-based technology, the signallevel is inversely proportional to the second power of the length of thesignal propagation path. This results in a dramatic difference in thespatial sensitivity of the communication and means that with theinduction-based technology it is possible to recognize the portableapparatus 100 that wants to pair with the counterpart apparatus 106,whereupon the actual pairing may be performed with the radio-basedtechnology. A typical coverage of the induction-based communication isof the order of human dimensions, i.e. about 1.5 meters.

The induction-based transmitter 102 may be a kilohertz-rangetransmitter, a passive radio-frequency identification tag, or a nearfield communication transmitter, for example. Correspondingly, theinduction-based receiver 108 may be a kilohertz-range receiver, aradio-frequency identification tag reader, or a near field communicationreceiver, for example. The kilohertz-range transmission may operate at5-kilohertz frequency, for example. Higher frequencies, such as thoseexceeding 200 kilohertz, may also be possible. In an embodiment, thekilohertz-range includes 125 kilohertz. Near field communication mayrefer to a short-range high frequency wireless communication technology,known also as NFC, which enables communication over about a10-centimeter distance.

The radio transceiver 104, 110 may be a proprietary transceiver, or aBluetooth transceiver, for example. Emerging ultra low power Bluetoothtechnology may be used, as its expected use cases include heart ratemonitoring. The proprietary radio transmission may operate at2.4-gigahertz frequency, for example.

Next, the communication between the portable apparatus 100 and thecounterpart apparatus 106 is described as a communication sequence112-114-116-118-120-122-124. The communication sequence described inFIG. 1 is in no absolute chronological order. Other functions, notdescribed in this application, may also be executed within the sequence.Some parts of the sequence may also be left out or replaced by acorresponding part.

An identifier, associated with the radio transceiver 104 of the portableapparatus 100, needs to be known by the induction-based transmitter 102of the portable apparatus 100. This may be implemented in any suitableway: the identifier is communicated 112 during the use of the portableapparatus 100 from the wireless transceiver 104 to the induction-basedtransmitter 102, for example. This communication 112 may be implementedwith suitable interface technologies, such as a message interface,method interface, sub-routine call interface, block interface, or anymeans enabling communication between functional sub-units. Anotherpossibility is that the identifier is programmed in a memory of theinduction-based transmitter 102 during manufacture or service of theportable apparatus 100.

The radio transceiver 104 of the portable apparatus 100 may beconfigured to provide 114 its identifier to the radio transceiver 110 ofthe counterpart apparatus 106. However, this is not enough: as wasexplained in the Background section, there may be many portableapparatuses operating simultaneously and transmitting their identifiers,and as result of this, the counterpart apparatus 106 does not know withwhich portable apparatus it should be paired with. Picture the followingscenario in a health club: a user armed with the portable apparatus 100wishes to exercise with the counterpart apparatus 106, but thecounterpart apparatus 106 cannot decide whether it should be paired withthe identifier 114 transmitted by the portable apparatus 100 or withanother identifier 126 transmitted by another portable apparatus.

For that reason, the induction-based transmitter 102 of the portableapparatus 100 is configured to wirelessly provide 118 the identifier tothe counterpart apparatus 106 by a magnetic field, and theinduction-based receiver 108 of the counterpart apparatus 108 isconfigured to wirelessly obtain 118 the identifier from the portableapparatus 100 by the magnetic field.

In an embodiment, the counterpart apparatus 106 may first transmit 116 amagnetic field as a carrier to the portable apparatus 100, whereupon theportable apparatus 100 may modulate this carrier in order to transmit118 the identifier to the counterpart apparatus 106. In that case, theinduction-based receiver 108 of the counterpart apparatus 106 alsocomprises a transmitter (not illustrated in FIG. 1) configured totransmit the carrier. Such an embodiment may resemble reading of apassive RFID tag/transponder, where reading distances may vary from tencentimeters up to a few meters.

As illustrated in FIG. 1, the identifier received by the counterpartapparatus 106 is then provided 120 from the induction-based receiver 108to the radio transceiver 110 of the counterpart apparatus 106. Thiscommunication 120 may be implemented with suitable interfacetechnologies, such as a message interface, method interface, sub-routinecall interface, block interface, or any means enabling communicationbetween functional sub-units.

Now that the counterpart apparatus 106 knows with which portableapparatus 100 it needs to execute the pairing protocol, the next part ofthe sequence may be performed. The radio transceiver 104 of the portableapparatus 100 associated with the identifier is configured to execute122 the pairing protocol utilizing the identifier with the counterpartapparatus 106 by electric radiation, and the radio transceiver 110 ofthe counterpart apparatus 106 is configured to execute 122 the pairingprotocol utilizing the identifier with the portable apparatus 100 byelectric radiation.

Having been paired together, the portable apparatus 100 and thecounterpart apparatus 106 may now proceed to the last part of thesequence. The radio transceiver 104 of the portable apparatus 100 isconfigured to communicate 124 information with the counterpart apparatus106 by electric radiation, and the radio transceiver 110 of thecounterpart apparatus 106 is configured to communicate 124 informationwith the portable apparatus 100 by electric radiation. The informationmay be any data that the portable apparatus 100 and the counterpartapparatus 106 need to communicate to each other. The information may bespecific to a user of the portable apparatus 100, specific to theportable apparatus 100, or specific to the counterpart apparatus 106.The information may be heart activity data, which may include heart rateinformation, beat-to-beat intervals, and/or an electrocardiogram (ECG),for example. Other possible information include heart rate limits,calorie information, body temperature of the user, status of the batteryof the portable apparatus 100, training schedules, equipmentidentification information, user information, registration information,etc.

The identifier associated with the radio transceiver 104 of the portableapparatus 100 may be any identifier used in the pairing protocol. Theterm ‘pairing protocol’ refers here to any protocol that is used in adhoc based communication to recognize the parties of the communication.The identifier may be a medium access control (MAC) address of the radiotransceiver 104, or a part of a medium access control address of theradio transceiver 104. Bluetooth utilizes such MAC addresses, forexample.

Table 1 describes a unique 48-bit Bluetooth device address (LSB=Leastsignificant bit, MSB=Most significant bit). Such an address may beobtained from the IEEE Registration Authority. The device addresscomprises two main fields: a company_id field, and a company_assignedfield. The company_id field comprises two fields: UAP field and NAPfield. The company_assigned field comprises only one field: LAP field.

TABLE 1 Bluetooth device address (BD_ADDR) LSB MSB company_assignedcompany_id LAP UAP NAP 0000 0001 0000 0000 0000 0000 0001 0010 0111 10110011 0101

As was earlier described in connection with the communication sequence,the radio transceiver 104 of the portable apparatus 100 may beconfigured to provide 114 its identifier to the radio transceiver 110 ofthe counterpart apparatus 106. In Bluetooth, this may be performed in aso-called promiscuous mode. This has an effect that the radiotransceiver 110 of the counterpart apparatus 106 knows all identifiersof those portable apparatuses that are within the reception range. Forthat reason, it may be so that only a part of the MAC address needs tobe transmitted 118 as an identifier by the induction-based transmitter102 of the portable apparatus 100. The induction-based transmitter 102may be configured to wirelessly provide 118 a predetermined number ofthe least significant bits of the medium access control address of theradio transceiver 104, and the induction-based receiver 108 may beconfigured to wirelessly receive 118 the predetermined number of theleast significant bits of the medium access control address of the radiotransceiver 104.

Let us take three example addresses, from which only the 16 leastsignificant bits are shown:

-   -   address 1: 01101010 10101011;    -   address 2: 11001101 10101000; and    -   address 3: 11001101 00000000.

The predetermined number of the least significant bits could be 7 bits,for example. The first of these bits may start after the first bit thathas the value one starting from the least significant bit. These bitsare in bold and they are underlined in the example addresses.

Next, FIGS. 2, 3 and 4 illustrate various embodiments of the portableapparatus 100 and the counterpart apparatus 106, wherein the portableapparatus 100 is implemented as a heart rate monitor. Polar Electro®(www.polarusa.com) designs and manufactures heart rate monitors andtheir accessories. At the time of filing this patent application, theapparatus may be implemented based on a Polar WearLink® transmitterW.I.N.D., which is a textile transmitter belt 202 worn around the chestof the user 200 to transmit heart activity data, and on a Polar RS800sdRunning Computer, which is a user interface unit 204 of the heart ratemonitor. The transmission of the heart activity data may utilize theprinciples of time division and/or packet transmission, for example.

The user interface unit 204 may be worn around the wrist, like a watch,but it may well be implemented to another kind of platform, such as asubscriber terminal of a radio system: a mobile telephone for example.The user interface unit 204 may also be a sports watch for use as aninstrument in sports.

FIG. 2 describes an embodiment, wherein the heart rate transmitter 202wearable on the chest of the user 200 comprises both the induction-basedtransmitter (=a kilohertz-range transmitter, for example) 102 and theradio transceiver (=a Bluetooth transceiver, for example) 104. First,the Bluetooth transceiver may transmit 114 its identifier (BD_ADDR, forexample) to the counterpart apparatus 106. Next, the heart ratetransmitter 202 may utilize the kilohertz-range transmitter to transmit118 the identifier of the Bluetooth transceiver (7 bits of the BD_ADDR,as described above, for example) to the counterpart apparatus 106. Thecounterpart apparatus 106 is then able to identify the correct portableapparatus 100. The heart rate transmitter 202 (or to be precise, itsBluetooth transceiver) and the counterpart apparatus 106 may then bepaired 122 with each other, whereupon information communication 124 maystart.

FIG. 3 describes an embodiment, wherein the user interface unit 204comprises both an induction-based transmitter (=a passiveradio-frequency identification tag, for example) 102 and the radiotransceiver (=a Bluetooth transceiver, for example) 104. First, theBluetooth transceiver may transmit 114 its identifier (BD_ADDR, forexample) to the counterpart apparatus 106. Next, the passiveradio-frequency identification tag may provide 118 the identifier of theBluetooth transceiver (BD_ADDR, or a part of it as described above, forexample) to the counterpart apparatus 106. The earlier described carriermechanism 116 may be used here as well. The counterpart apparatus 106 isthen able to identify the correct portable apparatus 100. The userinterface unit 204 (or to be precise, its Bluetooth transceiver) and thecounterpart apparatus 106 may then be paired 122 with each other,whereupon information communication 124 may start.

FIG. 4 describes an embodiment, wherein the heart rate transmitter 202wearable on the chest of the user 200 comprises the induction-basedtransmitter (=a kilohertz-range transmitter, for example) 102, and theuser interface unit 204 comprises the radio transceiver (=a Bluetoothtransceiver, for example) 104.

First, the Bluetooth transceiver may transmit 114 its identifier(BD_ADDR, for example) to the counterpart apparatus 106. Next, the heartrate transmitter 202 may utilize the kilohertz-range transmitter totransmit 118 the identifier of the Bluetooth transceiver (7 bits of theBD_ADDR, as described above, for example) to the counterpart apparatus106.

The identifier may be transmitted as stand-alone information, or encodedwithin a stream of heart activity data. Encoding is described in twoother patents of the applicant: U.S. Pat. Nos. 5,611,346 and 5,632,279.

As was explained earlier, the identifier may be associated with theradio transceiver 104 of the portable apparatus 100. However, otherembodiments are also feasible. In an embodiment, the identifier isassociated with the portable apparatus 100. The identifier may be anyinformation which is transmitter both by the induction-based transmitter102 and the radio transmitter 104. The counterpart apparatus 106 maycompare the identifiers obtained from the radio transceivers with thoseobtained from the induction-based transmitter 102 and establish aconnection or start data transfer with such a radio transceiver thattransmits an identifier matching with an identifier communicated by theinduction-based transmitter 102. In an embodiment, the identifier is anidentifier of the induction-based transmitter 104. The identifier maydefine a transmission channel of the induction-based transmitter 102.The code space defining the possible identifiers of the transmissionchannel of the induction-based transmission may be rather limited. Ifthe same code occurs twice or more frequently in the counterpartapparatus 106, the counterpart apparatus 106 may transmit an enquirymessage to the portable apparatus 100 in order to obtain additionalidentifiers. Such identifiers may be based on heart rate information,such as time interval of successive heart pulses.

The counterpart apparatus 106 is then able to identify the correctportable apparatus 100. The user interface unit 204 (or to be precise,its Bluetooth transceiver) and the counterpart apparatus 106 may then bepaired 122 with each other, whereupon information communication 124 maystart.

It is to be noted that in this embodiment the heart rate transmitter 202may continue to transmit 400 heart activity data.

It is to be noted that when the separate transmitter belt 202 and userinterface unit 204 are used, the processing of the heart activitymeasurements may be distributed between the transmitter belt 202 and theuser interface unit 204. The choice of the distribution depends on theprocessing power and power consumption requirements and on thetransmission capacity, and it may have an effect on how the describedcommunication is best implemented.

The implementation of the earlier described embodiments in such anexisting product requires relatively small and well-definedmodifications. Only the above-described communication needs to beimplemented. Naturally, as the products evolve, the feasible platformsfor the implementation of the embodiments described in this patentapplication also evolve and emerge.

Other implementations may also be possible. The heart rate monitor mayalso be implemented so that, instead of the solution comprising thetransmitter belt 202 and the user interface unit 204, the heart rate maydirectly be measured from the wrist on the basis of the pressure, forexample. Other ways for measuring the heart rate may also be employed.As sensor technology becomes more integrated, less expensive, and itspower consumption characteristics are improved, the sensor measuringheart activity data may also be placed in other arrangements besides thetransmitter belt 202. Polar Electro® is already marketing clothes thatmay be provided with separate small sensor units wirelesslycommunicating with the wrist unit 204.

The portable apparatus 100 may be a part of a heart rate monitor formeasuring the user's heart rate and possibly other parameters that canbe measured non-invasively (such as blood pressure). In U.S. Pat. No.4,625,733, which is incorporated herein by reference, Säynäjäkangasdescribes a wireless and continuous heart rate monitoring concept wherea transmitter to be attached to the user's chest measures the user'sECG-accurate (electrocardiogram) heart rate and transmits the heart rateinformation telemetrically to the heart rate receiver attached to theuser's wrist by using magnetic coils in the transmission.

Next, a communication method will be described with reference to FIG. 5.The operations described in FIG. 5 are in no absolute chronologicalorder. Other functions, not described in this application, may also beexecuted between the operations or within the operations. Some of theoperations or parts of the operations may also be left out or replacedby a corresponding operation or part of the operation. The method startsin 500. In 502, an identifier of a radio transceiver is wirelesslycommunicated from a portable apparatus to a counterpart apparatus by aninduction-based magnetic field. In 504, a pairing protocol utilizing theidentifier is executed between the radio transceiver of the portableapparatus and a radio transceiver of the counterpart apparatus byelectric radiation. In 506, information is communicated between theradio transceiver of the portable apparatus and the radio transceiver ofthe counterpart apparatus by electric radiation. The method ends in 508.The above-described embodiments of the apparatuses may also be used toenhance the method.

As technology advances, the inventive concept can be implemented invarious ways. The invention and its embodiments are not limited to theexamples described above but may vary within the scope of the claims.

1. A portable apparatus comprising: an induction-based transmitterconfigured to wirelessly provide an identifier to a counterpartapparatus by a magnetic field; and a radio transceiver configured toexecute a pairing protocol utilizing the identifier with the counterpartapparatus by electric radiation, and to communicate information with thecounterpart apparatus by electric radiation.
 2. The portable apparatusof claim 1, wherein the induction-based transmitter comprises akilohertz-range transmitter, a passive radio-frequency identificationtag, or a near field communication transmitter.
 3. The portableapparatus of claim 1, wherein the radio transceiver comprises aproprietary transceiver, or a Bluetooth transceiver.
 4. The portableapparatus of claim 1, wherein the identifier comprises an identifierassociated with the radio transceiver, an identifier associated with theportable apparatus, an identifier of the induction-based transmitter, anidentifier defining a transmission channel of the induction-basedtransmitter, a medium access control address of the radio transceiver,or a part of a medium access control address of the radio transceiver.5. The portable apparatus of claim 4, wherein the induction-basedtransmitter is configured to wirelessly provide a predetermined numberof the least significant bits of the medium access control address ofthe radio transceiver.
 6. The portable apparatus of claim 1, wherein theinformation comprises information specific to a user of the portableapparatus, information specific to the portable apparatus, orinformation specific to the counterpart apparatus.
 7. The portableapparatus of claim 1, wherein the portable apparatus comprises anelectronic circuit, a heart rate monitor, a heart rate transmitterwearable on the chest of a user, a personal measurement device, awrist-worn measurement device, or a subscriber terminal of a radiosystem.
 8. A counterpart apparatus comprising: an induction-basedreceiver configured to wirelessly obtain an identifier from a portableapparatus by a magnetic field; and a radio transceiver configured toexecute a pairing protocol utilizing the identifier with the portableapparatus by electric radiation, and to communicate information with theportable apparatus by electric radiation.
 9. The counterpart apparatusof claim 8, wherein the induction-based receiver comprises akilohertz-range receiver, a radio-frequency identification tag reader,or a near field communication receiver.
 10. The counterpart apparatus ofclaim 8, wherein the radio transceiver comprises a proprietarytransceiver, or a Bluetooth transceiver.
 11. The counterpart apparatusof claim 8, wherein the identifier comprises an identifier associatedwith the radio transceiver of the portable apparatus, an identifierassociated with the portable apparatus, an identifier of theinduction-based transmitter, an identifier defining a transmissionchannel of the induction-based transmitter, a medium access controladdress of the radio transceiver, or a part of a medium access controladdress of the radio transceiver.
 12. The counterpart apparatus of claim11, wherein the induction-based receiver is configured to wirelesslyreceive a predetermined number of the least significant bits of themedium access control address of the radio transceiver.
 13. Thecounterpart apparatus of claim 8, wherein the information comprisesinformation specific to a user of the portable apparatus, informationspecific to the portable apparatus, or information specific to thecounterpart apparatus.
 14. The counterpart apparatus of claim 8, whereinthe counterpart apparatus comprises an electronic circuit, a computer,an exercise apparatus, or a health club apparatus.
 15. A communicationmethod comprising: communicating wirelessly an identifier from aportable apparatus to a counterpart apparatus by an induction-basedmagnetic field; executing a pairing protocol utilizing the identifierbetween the radio transceiver of the portable apparatus and a radiotransceiver of the counterpart apparatus by electric radiation; andcommunicating information between the radio transceiver of the portableapparatus and the radio transceiver of the counterpart apparatus byelectric radiation.
 16. A portable apparatus comprising: means forwirelessly providing an identifier to a counterpart apparatus by aninduction-based magnetic field; and means for executing a pairingprotocol utilizing the identifier with the counterpart apparatus byelectric radiation, and for communicating information with thecounterpart apparatus by electric radiation.
 17. A counterpart apparatuscomprising: means for wirelessly obtaining an identifier from a portableapparatus by an induction-based magnetic field; and means for executinga pairing protocol utilizing the identifier with the portable apparatusby electric radiation, and for communicating information with theportable apparatus by electric radiation.